The present invention relates generally to micro fabrication techniques. More particularly, the invention provides a method and device for manufacturing a fluidic sensing device using a micromachining method and apparatus. Merely by way of example, the invention has been applied to the manufacture of a polymer based capacitive fluidic sensing device. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to other applications.
A Micro-Electro-Mechanical System, commonly called MEMS, is generally a batch-fabricated (micro fabricated) system that includes both electrical and mechanical elements. MEMS elements often have characteristic sizes ranging from nanometers to millimeters. MEMS often makes possible certain systems that are smaller, faster, more economical, and energy efficient in some cases. In a general MEMS system, the electrical portion includes integrated circuits, which forms the thinking part, while the electro-mechanical portion works with the thinking part to control functions and perception.
MEMS generally includes micro sensors and actuator devices. Micro sensors often gather outside information such as thermal, biological, optical, gravitational, and others. Actuators often respond to user based information to control their environment. As merely an example, capacitive sensing devices are common examples of MEMS. Capacitive sensors have been applied to micro fluidic applications in the form of pressure sensors and flow sensors based on a differential pressure principle. Also, capacitive sensing has been utilized in applications such as fluid level sensing, determination of ion concentration, and for measuring the makeup of mixtures, such as oil and water. The conventional capacitive sensors are usually lacking in flexibility and difficult for total system integration.
From the above, it is seen that techniques for manufacturing improved MEMS devices is highly desirable.